One or more embodiments are directed to an artificial turf system that uses support material for an infill layer.
Natural grass turf has been traditionally used for athletic events. However, natural grass typically does not grow well within shaded areas or enclosed stadiums. Also, high traffic areas on natural grass wear out rapidly creating muddy or dusty areas on the field.
Artificial turf is commonly used on athletic fields instead of natural grass turf. Artificial (or synthetic) turf was developed to mimic the look and feel of natural grass. However, artificial turf is generally more durable and less expensive to maintain than natural grass.
Artificial turf generally involves a carpet-like pile fabric having a backing laid on a compacted substrate, such as small stones or rocks or other stabilized base material. The pile fabric has rows of upstanding turf fibers or synthetic ribbons representing grass blades extending upwardly from the backing. The backing typically includes small holes or perforations to allow water to drain through the turf.
Various formulations of infill have been interspersed among the turf fibers on the backing to simulate the presence of soil. Most types of infill have used various combinations of sand, small rocks and resilient particles. For example, U.S. Pat. No. 4,337,283 discloses an artificial turf having a pile fabric, and a top-dressing layer comprising a mixture of from 25 to 95 volume percent resilient particles such as rubber, and from 5 to 75 percent volume sand. This top-dressing layer is interspersed among the pile elements or turf fibers on the backing. The top-dressing layer may operate to stabilize or prevent movement of the turf, to absorb shock and impact of players, and to improve footing. As another example, U.S. Pat. No. 5,958,527 discloses an artificial turf having an infill with several layers, including a base course of sand and/or small rocks and a top course of resilient particles.
There are several potential problems with the use of sand and rocks in an infill layer. Sand and rocks can be abrasive and/or have rough edges, which may damage the turf fibers and backing. In addition, sand or small particles can become lodged in backing perforations, which can prevent proper drainage of water from the turf. This may cause water to accumulate on the turf and resilient particles in the infill to float during rainfall. The use of an infill layer of sand and/or rocks, typically having uneven sizes and shapes, creates unpredictable drainage characteristics. Sand and rocks in a turf infill may also absorb body fluids (such as blood) and other contaminants, and therefore, may